Electrochemical Stability and Degradation of Commercial Pd/C Catalyst in Acidic Media

Palladium has attracted significant attention as a catalyst or co-catalyst for many electrochemical reactions in energy conversion devices. We have studied stability of commercial Pd/C sample an acidic electrolyte by exposing it to accelerated stress test (AST) mimic potential spikes fuel cells and electrolyzers during start/stop events. AST consisted extensive rapid cycling (5000 cycles, 1 V/s) two regions, namely AST1 was performed between 0.4 1.4 VRHE, while AST2 0.05 VRHE. Degradation monitored the changes Pd surface area, hydrogen evolution reaction (HER) used observe corresponding impact degradation on activity Pd/C. Significant HER loss were observed both regions. Coupling flow cell with inductively coupled plasma mass spectrometry device showed substantial dissolution ASTs. Identical location scanning electron microscopy revealed that is followed redeposition ASTs, resulting particle size growth. Particle growth seen especially dramatic case AST2, when particularly large nanostructures obtained top layer. According results presented this work, (in)stability other Pd-based nanocatalysts should be systematically may present key factor limiting their application